Electric-arc welding



L. J. STEELE ET AL I ELECTRIC ARC WELDING Filed Jafi. 14, 1922 4 Sheets-Sheet 1 Inventors ,6]. M

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L. J. STEELE ET AL ELECTRIC ARC WELDING Filed Jan. 14. 1922 4 Sheets-Sheet 2 Jan. 20. 1925 I 1,523,666

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Y L. J. STEELE ET AL ELECTRIC ARC WELDING Filed Jan. 14, 1922 4 Sheets-Sheet 4 Fig.6.

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Patented Jan. 20, 1925.

UNITED STATES PATENT OFFICE.

LOUIS JOHN STEELE, O'F PORTSMOUTH, AND HAROLD MARTIN AND ANDREW EDWARD MCCARTHY, OF SOUTHSEA, ENGLAND, ASSIGNORS TO HANDSTOOK LIMITED, OF LONDON, ENGLAND, A CORPORATION OF GREAT BRITAIN AND IRELAND.

ELECTRIC-ARC WELDING.

Application fi1ed January '14, 1922. Serial No. 529,272.

T all whom it may concern;

Be it known that we, LOUIS JOHN STEELE, I'IAROLD MARTIN, and ANDREW EDWARD MoCAn'rnY, subjects of the King of Great 5 Britain and Ireland, residing respectively at H. M. Dockyard, Portsmouth, in the county of Hants, England, Helena Road, Southsea, in the county of Hants, England, and Lyonsdown, Haslemere Road, South- 10 sea, in the county of Hants, England, have invented certain new and useful Improvements in and Relating to Electric-Arc Welding, of which the following is a specification.

in a process or method of electric welding with automatic timing and /or control of the are, which process or method is especially applicable to the fitting of metal studs, tubesor the like, of iron, steel, or brass, to metal bodies, whether forged or cast, such as metal sheets, plates, bars, blocks, forgings and castings.

The process or method consists in the forstud or tube or the like and the body or the like to which the stud or the like is to be welded, the maintenance of the said arc for a suitable length of time, the periodof which is predetermined and automatically controlled and the subsequent forcing of the end of the molten metal stud or the like againstthe molten metal body or the like. For convenience of descri tion, the stud or tube or the like is hereina ter referred to as the stud, and the metal body, plate or the like, to which the stud is to be welded, is hereinafter referred to as the plate.

According to the invention a stud moving and are striking device is provided for operation pneumatically or by fluid pressure under the control and timing of mechanical means operating automatically. The stud holder or chuck is carried from a piston dispressure can be admitted to effect movements of the piston in either direction as required by the sequence of operations of moving the stud from the plate to strike the arc and returning the stud to the plate to effect the weld.

According to the invention, also, the ad- This invention relates to apparatus for use.

mation of an electric are between the metal posed within a cylinder, to which air or fluid" mission and exhaust of the air or fluid ressure to or from the cylinder is efiecteg by valves operated automatically by mechanical means advantageously comprising rotatable cams, the rotation of which is effected by electrically operating or electrically 0on trolled driving mechanism.

The valves may comprise separate operating and isolating valves, the first of which serves for the admission of air or fluid pressure to either of the two sides. of the piston while the second serves for cutting 011' or opening communication between the operat-- ing valve and the source of air or fluid pressure. The two valves, however, may be combmed to torm a single valve, the operating of one construction of the stud moving and are striking device.

Figure 2 is a sectional elevation at right angles to Figure 1.

Figure 3 is a diagram representing the relative disposition and form of the operating cams of the automatic control and timing apparatus.

Figure 4 is a sectional elevation of a modified arrangement of the controlling valves and automatic control and timing apparatus.

Figure 5 is a diagram representing the form and relative disposition of the operating cams of the automatic control and timing apparatus represented in Figure 4.

Figure 6 is a diagram of the electrical connections for the construction of apparatus illustrated in Figures 1 to 8.

The apparatus broadly comprises two suitable for attachment to, though insulated from, a movable spindle or slide such as. that of a drilling machine, and has rigidly the period of the arc is automatically maintained at any desired predetermined value until the apparatus is re-set,

In the construction of the apparatus according to the invention illustrated in Figures 1 to 3 of the accompanying drawings, the stud moving and are striking device is connected to it the necessary control valves actuated by an automatic timing mechanism,

andconnected to a source of compressed air by a flexible tube or pipe.

The stud moving and are striking device consists of a cylinder a containing .piston b and piston rod 6 which latter passes through suitable glands in the centre of the cover plates a a at the upper and lower ends of the cylinder. At the lower and outer end of the piston rod 7) is fitted a suita le chuck or other stud'holding device If. The

upper cover plate a of the cylinder-carries upon a bracketa anad ustable arc length setting and limiting device, comprising a.

screwed plug a with a central bore closed at the upper end and containing a spring 0 pressing upon a plunger 0 which protrudes from the plug to an extent determining the exact required length of arc.

The two control valvesd, e, which are of the piston type, are disposed in suitable cylindrical valve casings d 6 of which the casing d is connected by way of two ports through pipes d d with corresponding ports in the upper and lower cover plates of the cylinder (1, and the casing e is connected through a suitable port-with an air supply fitting e and provided with a second port 63 for communication with the atmosphere. The valve e serves as an insulating valve and functions to connect the casing d of the other or operating valve d either to the air supply for the apparatus, when in its upper position, or alternatively to atmosphere, When' in its lower position. The operating valve 0? serves, when .in its lower position, to connect the space in the cylinder a at the under-side of the piston b with the casing e of the isolating valve e, and the corresponding cylinder space at the up er side of the piston 7) to atmosphere. (,onversely, when in its upper position, the operating valve d connects the cylinder space at the upper side of the piston 12 to the casing 61 of the isolating valve 6 and the cylinder space at the under-side of the piston 7) to atmosphere. Operating rods (1, e are fitted to and above the control valves and springs f are arranged below the valves, so that both valves tend to ris to their higher positions, The casings al e are closed at both ends and provided with air portsd eithe ports (Z serving for the exhaust to atmosphere and the ports a to permit fre movement of the valve 6.

The automatic control and timing apparatus comprises a rotatable spindle g on which are-fixed suitable cams h, i, which operate in conjunction with the rods dfe, respectively, of the control valves to permit thelatter to rise under the action ofthe springs f as necessary. The cam spindlevis rotated at a constant peed through suitable 20111, such as a worm and worm wheel gear by means of an electric motor 9 or other suitable form of motor controlled electrically. To effect the sequence ofo-perations required for a weld it is necessary that the cam spindle f/ of the timing apparatus should makeone complete revolution. The motor control circuit. istherefore carried through a contact disc or cam j mounted up- I on the spindle and having a gap j in its periphery. The disc or cam j co-operates with an'iusulatcd contact finger or brush 7' hen, therefore, after a complete revolutionot the cam spindle g. the gap j comes opposite the finger or brush 7' the motor control circuit is broken and the rotation of the motor arrested. The rotation of the motor and thusof the cam spindle may be starte for each weld by operation of a. push button or other switch which completes the motor control circuit until the finger or brush j makes contact with the disc or cam j. -'A

cam in, also fitted on the. spindle g, operates and the bell crank lever when the valves rise and the welding circuit-"is closed are sudden and for this purpose the edges of the cams are at the required points formed with radial edges, the relative disposition of the radial edges of the cams 2' and is being such that the bell crank lever is thrown over to close the welding circuit, immediately before the valve 6 rises to place the cylinder m in communication with the supply through the fitting e by way of the pipe (P. In order that the time period of the arc may be varied as desired, it is necessary to provide means whereby the movement of the valve 1: may be cflected at different points in the revolution of the cam spindle g. For this purpose the cam 2' is duplicated by a cam 2' which is loosely mounted upon the spindle g and dis posed in contact with the cam 2' to which it is ing circuit should be varied accordingly. For

this purpose the cam 72 is similarly dupli cated by a cam 70 which is mounted loosely upon the spindle g and in fixed relation to the cam 71 to which it may be secured by a sleeve fitting upon the spindle. Any adjustment of the cam it with reference to the cam 11 therefore involves corresponding adjustment of the cam k to the cam lathus ensuring that the closure of the main welding circuit takes place at the right instant relatively to the striking of the arc.

, It will be understood that variations may may be so provided that the movement of r the valves may be effected entirely by the cams or that the lifting of the valves may be efiectedby the cams and the'return movement effected by spring action. I

As illustrated in Figures 4 and 5 the isolating and operating valves may be combined as a single or double valve Z disposed in a corresponding'valve casing Z and the cams h and iare replaced by a compound cam Z serving first to permit the valve to rise in order to admit the pneumatic or fluid pressure into the cylinder a below the lower face of the piston 79 and then to depress the valve past its initial position until communicationis opened between the source of pneumatic or fluid pressure and the upper space of the cylinder a. The cam Z for this purpose is formed with a portion Z which projects beyond the circumferential line corresponding to the initial position of the valve. In order to permit adjustment of the time period of the arc the same means as that described with reference to Figures 1 to 3 may be provided, that is, a cam Z. is mounted loosely upon the spindle g in contact with the cam Z to which it is secured in its adjusted position by means of a stud and slot connection. The cam Z is, as before, rigidly connected with the cam it Referring to Figure 6 it will be seen that an electro-1nagnetically actuated contactorm, reactance coil '21 and adjustable rheostat 0 are included in the main welding clrcult 1n series with the stud p and plate g while in a parallel or control circuit is inserted the operating coil m of the contactor in series with the switch 1- and a fuse 0 Similarly a. motor circuitis provided in parallel to the said control circuit passing through the motor 9 and the contact finger 3' and thence by way of the cam j and the spindle g to the fuse to, the field of the motor being in shunt across the motor armature and the spindle 9. To permit the starting of the motor, when the contact finger j is opposite the gap j of the cam j, the press button switch g is provided, with plug contacts for introduction into plug sockets g which are in circuit between the fuse 0 and, the contact finger y' The reactance coil. n serves to prevent the sticking of the stud p to the plate 9 and thus facilitates the drawing of the are by delaying the otherwise extremely rapid rise in the value of the cur-- rent of the main or welding circuit when the main switch or contactor is closed with the stud in contact with the plate and with a sufiicientlylow resistance in circuit to enable the requisite welding current to flow after the arc is struck. Apart from these effects the reactance coil is of value general- 1y in resisting rapid fluctuations in both the current and the voltage of the arc. Means may be provided such as a switch n for short circuiting the reactance coil when desirable.

In operation, after the stud p has been insorted in the stud holder or chuck b the stud moving device is placed so that the stud is held in correct position against the plate 9, the stud moving device being then clamped or locked in position. The are striking and limiting device is then adjusted, and assuming that necessary adjustments of the rheostat and timing apparatus have been made to regulate both the current and time period of the arc, the automatic timing and control apparatus is now, started by means of the push button or switch 9 which closes the motor circuit, setting the motor in operation to rotate the spindle g. The closure of the motor circuit is then maintained by the cam plate 7'. During the ensuing rotation of the cam spindle g of the control apparatus the following sequence of operations takes place l. The contactor operating coil circuit is closed at the switch 10 by the cam'lc, through the lever 7%, thereby closing the main circuit throughthe stud p and plate 9 by means of the contactor n.

2. The isolating valve 0 rises, thereby admitting compressed air to the cylinder (L at the under-side of the piston b carrying the stud holder or chuck b and stud, which therefore is moved away from the platethus striking an arc.

3. The operating valve d lifts, thus connecting the cylinder space at the under-side of the piston b to atmosphere and the cylinder space at the .upper side of piston to the supply of compressed air which thereby forces the molten end of the stud 6 into or on to the molten plate 9 to which it becomes welded.

4. The contactor control circuit is now opened by the action of the cam 7r upon the lever. 70 and switch 75- thereby opening the .main welding circuit through the stud andplate.

5. The isolating valve 6 is now depressed by the cam i thereby connecting the operating valve casing and the cylinder of the stud moving device to atmosphere.

(i. The operating control valve (Z is depressed by the cam it to the normal position.

7. The circuit of the motor g is opened when the gap j in the cam 7' comes opposite the contact finger j thereby stopping the apparatus, after one complete revolution, in the same position at which it started.

Thestud-moving device is next released and withdrawn from the stud which has been welded to the plate.

An airreceiver is advantageously provided between the air supply main and the welding appartus and is provided with pressure gauge in regulating cocks and "valve-sin o1 ":er that the air pressurein the stud moving apparatus may be ad usted to suit the size and nature of the weld which is being made, with due regard to the area of the stud moving piston.

j The mechanical pressure required to make satisfactory welds increases generally in proportion to the cross-sectional area of the stud which is to be welded, and is much greater for metals such as steel and iron thanfor metals with lower melting points such as brass or aluminium. The force required to complete the weld is much greater than that necesary to move the stud away from the plate and Strike the are, and on this account the stud may be moved away from the plate by means of a small auxiliary piston and cylinder on the underside of the main piston and cylinder, or alternatively, if so desired, a reduced pressure relief valve may be fitted in the cylinder at the under-side ofthe main piston. The automatic control and timing apparatus may be started and/or actuated by electrical, me chanical pneumatic or hydraulic means, or any desired combination thereof. The movements' of the stud may also be effected by pneumatic, hydraulic, mechanical, electrical or electro-magnetie means or any combina-v tlon thereof.

The use of pneumatic pressure to return the stud to the plate ensures the weld being made under adequate pressure without hammering. This may be most conveniently and simply done by the control of the pressure fluid, as, for example, by admitting it into" For the purpose of welding long bars or tubes and the like, it may be necessary to pass these through the centre ofthe studmoving device, and in such cases the studm'oving device is'preferably provided with a hollow piston rod at the end of which is attached the stud holder; As the use of such a hollow piston rod involves modifications in the design of either of the types of stud-moving -device described,.such as the provision of additional glands and an alteration inthe arrangement of the arcstrikmg and limiting device, alternative-arrangements have to be adopted. These arrangements require (a) The stud holder to be fixed at the end of a hollow circular red, the latter being free to slide in a suitable guide or guides and the necessary movements ofithe stud being ellected by mechanically connecting the moving device such as those previously described, which in this case would be required" to operate in pairs'in parallel.

To facilitate welding by the method or means of this invention, more particiilarly when steel and iron studs have to be welded,

brass rings 01' bushes may be'fitted at the welding ends of the studs with a short length of the'stud projecting. In use these rings appear to steady the arc, enlarge the crater of molten metal and generallyt'acilitate the making of welds, which are free from blowholes or other defects, especially with small studs. The welding of small studs can also be facilitated by making them hollow, that is, in the form of thick tubes either throughout their length or simply adjacent to the weld. Though a smaller cross sectional area of metal is obviously thus obtained at the weld, this iscompensated for by the quality of the weld and the greater facility with which it is made.

'Theinsertion of a small disc or ball of brass or other suitable metal between the stud and plate immediatelybefore malcin a weld, particularly in the case of steel stu welding, is advantageous to prevent any tendency of thestud to become tacked to .the plate when the welding circuit is first closed. At the same time the use of a disc or ball in this manner renders it possible to vary the quality of the weld, if necessary, by making additions of metal or other substances to it.

It will be understood that the invention is hereinbefore described in terms involving reference to actual constructional embodiments of the invention and that the invention is not limited thereto.

The mechanical automatic control and timing apparatus hereinbefore described may, for example, be operated by a clockwork or other motor adapted to drive the cam spindle direct or through suitable gearing, the operation being controlled by such means as a solenoid brake, a mechanically operated stop device or by other suitable means. Such apparatus also may be employed with a mechanically operating studmoving and arc-striking device wherein the stud holder may be withdrawn for striking the arc by lever mechanism or by cam mechanism which may operate against spring action serving to return the stud to effect the weld, and actuated by suitable motor or other driving means under the control of the automatic timing apparatus.

The invention is applicable tothe production and manufacture of cinematograph reels, parts of motor road vehicles, ferrules for umbrellas and sticks, fishing or other reels, parts of aeroplanes, parts and terminals of electrical apparatus, as well as for numerous applications to ships and other general purposes in the arts.

We claim:

1. A method of electrically welding metallic studs and the like to metallic bodies wherein the stud is moved through the path of an electric are formed between the metallic body and the stud or the like into con tact with the metallic body so as to efi'ect the welding of the stud thereto, in which the sequence and duration of the operations involved in the welding are controlled by nonelectrical means, operating automatically, substantially as described.

2. A method of electrically welding metallic studs and the like to metallic bodies wherein the stud is moved through the path of an electric are formed between the metallic body and the stud or the like into contact with the metallic body so as-to effect the welding of the stud thereto, in which the sequence and duration of the operations involved in the. welding are controlled by mechanical means operating automatically, substantially as described. 1

3. A method of electrically welding metallic studs and the like to metallic bodies wherein the stud is moved through the path of an electric are formed between the metallic studs and the like to metallic bodies wherein the stud is moved through the path of an electric arc formed between the metallic body and the stud or the like into con tact with the metallic body so as to effect the welding of the stud thereto, in which the welding current is maintained until the Weld is effected, substantially as described.

5. An apparatus for electrically welding metallic studs and the like to metallic bodies wherein the stud is moved through the path of an electric are formed between the metallic body and the stud or the like into contact with the metallic body so as to elfect the welding'of the stud thereto, having mechanical means for effecting the necessary" movements of the stud holder, substantially as described.

6. Apparatus for use in the process of electric welding ashereinbefore described, wherein the stud is forced into contact with the body to which it is to be welded by means acting under fluid pressure.

7. Apparatus for electric welding, as set fortlrin claim 6. wherein the stud is withdrawn from the body to which it is to be welded for striking the arc and is returned into position for welding by means acting under fluid pressure, and under non-electrical control.

8. Apparatus for electric welding, as set forth in claim 7 wherein the control of the means acting under fluid pressure for moving the stud is effected mechanically.

9. Apparatus for electric welding, as set forth in claim 8, wherein the duration of the arc and the continuance of the closure of the welding circuit are adjustably determined.

10. Apparatus for electric welding, as set forth in claim 7, wherein the stud moving and are striking device comprises a cylinder and piston arrangement adapted to effect the movement of a stud holder, the admission of pneumatic or fluid pressure to the cylinder being controlled by non-electrically operated valves.

11. Apparatus for electric welding, as set forth in claim 10, wherein the valves are' operated through cams mounted upon a rotatable shaft.

12. Apparatus for electric welding, as set forth in claim 7 wherein the weldin circuit is closed by means of a mechanically operated switch under control of a rotatable camde'vice.

13. Apparatus for electric welding, as set forth in claimll, wherein a cam with adjustable valve-operating surface is provided to determine the moment of the admission of pneumatic or fluid pressure to the stud moving and arc striking device.

14. Apparatus for electric welding, as set forth in claim 12, wherein the switch of the welding circuit is closed by a cam having an adjustable operating surface.

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15. Apparatusfor electric welding, as set forth in claim 11, wherein the cams are rotated by means of a motor under electrical control through a rotatable cam and contact device, v the ram being provided with a gapped surface to ;deternnne the rotation of forth in thepre'cding claim, wherein the 1 motor may be set into rotation by a switch the motor;

16. Apparatns for electric welding, as set device adapted for operation until the controlgin cam becomes. operative. Y i1 vided witha mechanically operating control device for controlling the sequence and duration of the operations involved in the welding and comprisin rotatable cams, the said cams being provi ed as pairs of elements whose relative position is capable of adjustment, substantially as hereinbefore described.

18. Apparatus for electric welding, as set forth in claim 10, wherein the admission and exhaust of pneumatic or fluid pressure with respect to both faces of the piston of the stud moving and are striking device are pparatus for electric welding, lproeffected under the control of two valves, one of which serves to control the supply of pneumatic or fluid pressure and the other the passage of pneumatic or fluid pressure to the respective faces of the piston, the valves being operated automatically by mechanical 19. Apparatus for electric welding, as set forth in claim 10, wherein the admission and exhaust of pneumatic or fluid pressure with reference tothe cylinder of the stud-moving and are striking device is controlled by a single valve operated automatically by mechanical means.-

-20. Apparatus for electric welding, as set forth. .in 'claim 18, wherein the valves are operated in one direction by cams and in the other direction by spring action. r 

